This proposal describes a new project to be undertaken involving research into the synthesis of biologically active molecules containing the cyclopentenone ring system. The key feature of this program lies in the development of a known but relatively unexploited organometallic cyclization reaction utilizing cobalt octacarbonyl to promote the co-oligomerization of carbon monoxide, acetylenes, and alkenes. One approach will involve study of cyclization reactivity of alkenes with strain introduced as a temporary structural feature (e.g., via a functionalized bridge), whereas other routes will utilize either intramolecularity or variations in electron density to promote useful reactivity. The products thus obtained are designed to be of value in the ultimate preparation of prostaglandins, antibiotics, antivirals, and cytotoxic agents of diverse structure based on the cyclopentenone unit. The proposed syntheses are structured for maximum efficiency using the most readily available, inexpensive starting materials, so as to represent potentially significant improvements over currently available methods in many cases.